Method of refining molten pig-iron.



J. B. NAU. METHOD OF REFINING MOLTEN PIG IRON APPLICATION FILED JAN. 18, 1911 Patented May 9, 1911.

J M KI ments, such for example as silicon,

phorus, sulfur, etc., may

UNITED dTATES OFFICE;

JOHN B. NAU, OF NEW YORK, N. Y.

METHOD Application To all whom it may concern:

Be it known that I, JOHN B. NAU, a citizen, of the United States, and a resident of .the borough of Manhattan, city, county, and

State of New York, have invented .certain new and useful Improvements in Methods of Refining Molten Pig-Iron, ofwhich the following is a specification. y :The object. 'of my present invention is to provide methods whereby undesired elepl10sbe removed from such iron with greater certainly within a less time, and ,with greater economy, than heretofore. I accomplish these objects by the 'methods of treatment hereinafter described,

the understanding of which will be facilitated by reference to 'the accompanying drawin s showing some forms of apparatus devised by me as adapted to facilitate the practice ofmy said novel methods, and for crucibles and either a stationary which. apparatus I have made application for Letters Patent, Serial No. 500,037, filed October 31, 1910.

My present invention relates particularly to the elimination, within limits, from molteirpig iron of such undesired elements as above referred to by bringing the same, as contained in said iron, into the presence of and intimate contact with oxygen compounds of iron, such for example as con- In Letters Patent No..

tained in iron ore. 786,048, granted to me March 28, 1905, I have described'and claimed such processes, and likewise in my pending application, Serial No. 518,014, filed September 16, 1909. In both of these {instances the refining method is practiced by aid of stationary or a stationary reservoir, these methods therefore sometimes necessitating undesired interruptions in the continuity of the process, and moreover also relatively less perfect and extended contact of the ends with the iron, during a given time, than is at tainable by my present methods hereinafter described. Moreover, in cases in which it is'desirable to accumulate a very consider-, able'body of resulting products including partially refined iron, and oxid containing slags for use in further refining operations, or other purposes, it may provedesirable to. maintain the contents of the fore-hearth of reservoir, throughout theirentire extent, at higher temperatures than sometimes practicableby means described in my said patfore-hearth or opening OF REFINING 'MOLTEN PIG-IRCN'.

Specification of Letters Patent. Patented May 9, 1911. filed January 18, 1911. serial 110 603335.

ent. My present methods are addressed to thesatisfying of such requirements, and, in their broadest HSPQCQfQOlIlPIlSG the imparting during the operation, and without intermissionthereof, such simultaneous move ment, or oscillation, "to the o'xids and the -metal as to promote to a higher degree than heretofore desired reactions, insure constant -movement of the oxids toward the positions required, separation from" the latter of the resulting refined metal and slag products and evacuation of the same from the apparatus when required wlthout interrupting the continuity of the operation, meantime maintaining in the resulting baths required temperature.

Referring now to the drawings showing forms of apparatus adapted to the practice of my present methods, Figure I is a plan view of the apparatus; Fig. II is a crosssection on line IIII of Fig. I; Fig. III is a cross-section on line III-III of Fig. II; Fig. IV is a cross+section on line IVIV of Fig. II.

I show in the drawings an organized apparatus which is one form of means capable of employment in the practice of my present methods and which electric tilting furnace comprising special features devised by sure the operation of, my process. This furnace is movably supported" by means of strong circular slides 1, fastened to the lower part of the furnace frame 9, on two parallel lines of rollers 2, carried in their turn by strong supports 3, only partly shown. The tilting of the furnace 1s obtained by any may be designated as an.

me to facilitate, and in-' suitable tilting device, which, owing to its for the understand style being immaterial 15 not shown n ing of my present invention, the drawings.

T he furnace proper 15 mainly composed of two parts, of which one a'crucible 4,

Said crucible is" surmountedpieces 0 ,quired height in said shaft.

5 also has preferably, but not necessarily, a

refractory lining inside an iron shell 10. Ore-shaft 5 is provided furthermore with a pig iron inlet 13 establishing communication between the inside of ore-shaft 5 and inlet spout lat suitably placed Where shown on top of compartment ll The center'of rotation' of the furnace may be placed at any suitable height, but' I consider it best to place it on or near the center line 13 of spout 14.

The electric current necessary for heating purposes in the furnace passes through electrodes 11 and 12 and may travel from either I have shown two sets of trodes 11= of one set enter the crucible through its top and electrodes 12 of the other set enten the fore-hearth through its roof.

The number ofelectrodes thus placed in one compartment may thus vary from one upward. Their location also may vary provided that the relative location remains such that the electric current going from one set to the otherpasses through the molten contents of the two-compartments 4 and 6 and of openings 8 in either direction. Gr indicates a source. of electricity and 11 12 conductors connecting same with said electrodes. My present improved method of refining molten pig iron is practiced :as follows. In any convenient suitable movable support or "container as for instance the crucible 4 I support in, and above, it as shown in the drawings as by ore-shaft 5 a normally 'continuous therefrom upwardly extending columxi of refining material consisting of a pervious ag regation of independently movable g substance containing oxid of iron as for instance preferably rich iron ore in solid pieces, or in the shape of concentrate ore briquets, resting upon the bottom of said crucible and piled up therefrom to any re- I then direct into said column of pieces of refining material a stream of molten pig iron in any convenient manner as for example by pouring said iron from the source wh'ence derived, asfor example the'blast furnace, into spout 14, whence it passes through inlet 13 and is projected thence by gravity through the un derlying portion of said column and into the crucible. The iron is thus caused to percolate in a number of small streams'through the ore column whence it will be accumulated in the crucible in the presence of the aggre ation of ore pieces contained in the latter.

uring and by these operations the iron will be, to an extent, mingled with and suiiiciently brought into the presence of and contact with the oxids of iron contained in the substance composing said column to produce in part the to be expected" reactions between the oxygen of the said oxids and the silicomphos phorus, sulfur, etc, desired to be removed from the iron, as will be understood by @565 skilled in'the metallurgical art; constantly accumulating 001 of resulting molten products, including partially refined iron, and slags containing oxid of iron, b

sides oxygen, ancl'other, compounds f he impurities mentioned, I next segregate or strain as far as practicable from out of said pieces of substance containing oxid of iron in the crucible in any convenient manner as for instance'by permitting said products to pass or flow through'the openings 8 in'the partition and thence into the fore-hearth 6, the partition 7 thus operating to substantially confine the bulk at least of the refining material in the crucible, the comparatively few pieces 'of refining material which may pass into the fore-hearth 6 being either there soon reduced or proving innoxious for the purposes to which the product is to be applied, and'this without interfering with the satisfactory performance and effects of the refining operations intended to take place in the crucible proper. 'While the foregoing operations are taking place I may, whenever and to the extent required, raise the temperature of the contents of the crucible and of the fore-hearth simultaneously to such cx'- tent as required to insure under all conditions the degree of fluidity required for the uses to which the final product is to be applied. Such raising of the temperature is, in this instance, accomplished, as will be readily understood, by causing the electric current to pass, in required degree. from the electrodes 11 to the electrodes 12, which is accomplished by turning on the current, the pathof which will pass downwardly and horizontally through the molten iron and slags contained in crucible 4, thence through those contained in the holes 8 and thence horizon tally and upwardly through the products contained in the fore-hearth to the cathodes 12, the resistance of the said contents thus causing generation of heat to the required extent throughout their midst.

lVhile the foregoingoperations are occurring I may impart movements to the refining material, to the iron, to the partially refined iron and to the resulting products by in this instance intermittently tilting or oscillating in alternately reverse directions and together and simultaneously the said crucible, fore-' hearth and shaft and thus their respective contents. By means of the movements thus imparted I cause the direction of the streams of molten iron down-flowing through the refining material to vary their courses relatively to the latter, thus insuring at this stage better and more complete contacts between the two than heretofore, with consequent promotion of desired reactions. and

through the shaft and into their position where required in the crucible which movement it will be observedis thus insured without the necessity of completely voiding the crucible. Moreover, by the said move-. merits-I am also enabled to evacuate to any desired extentthe'partly refined. iron and islags accumulated in the crucible and in the fore-hearth. It will thus be observed that I am by my present method for the first time s as I believe enabled to practice the refining desired in a substantially continuous operation and process, it being necessary only to keep, up constantly the supply of unpoured molten iron and thecharge of refining material in theshaft.

'It will of course be understood that any convenient means-may be employed for imparting 'to the refining materials, H011, and

re'sultantproducts, and in this instance to the'particular- "apparatus shown the required tilting or oscillating movements. It will also be understood by those-skilled in-"the artgtha-t preliminarily to the inception of the operation it is desirable i'n any usual and convenient manner to preliminarily heat the apparatus as well as the refining material as for instance in this case by burning gas or other appropriatefuelthrough the outlet 15 after the refining material has been charged or the refining material may be preliminarily heated before charging. It will also be '--unders'tood that a plurality ot 'holes or pas sages 8 in thepartition 7 is notabsolutely essential, a single aperture of sufficient size being, owing to the construction and the the .crucible.

aforesaid movements, competent to. withdraw boththe iron and the slag and segregate or strain them substantially from the,

main bulk of the refining material left in It will also be understood- -=that in cases in which the storage of the ;pa-rtly refined product and accompanying slags is not required, the fore-hearth 6 may of the refining material and their evacuation as far as to the position 17 substantially all accumulated liquid contents, including slag as well as iron, will be evacuated completely through the Spent 15. This not only'simplifies evacuation of the slag, but renders it,

possible to pour it, being of an excellent refining. nature, together with the iron, and thus take "both together from the refining apparatus to. the open-hearth furnace or *the pool is quickly diminished, these move otfierapparatus to bel'used' in refiningoperations. Thus the slag itself be- .comes, by my method, al'valuable" product,

ready to be used at once to the best advantage its liquid state. Thelocation of the centerof the inlet 13 approximately on the axis of rotation of the apparatus 13 renders it possible to tilt or oscillate the furnace so as to empty it completely of accumulated molten products without stop ping the inflow of the metal tobetreated, since, with the exception of the -rota-tioi.

' around its center,". spout l4 and inlet 13 remain stationary.

My present improved method also comprises inducing when required the descent of the refining materials toward and into the pool in whichthe lower portion of the ag-- grega'tio'n of said refinin-g 'materials is 'immersedbymanipulation of the body of the 35 pool so as to cause the same without sub stantial addition of molten. material to alternatcly immerse the said lower portions of said aggregation to greater and lessdepths. This, as will be perceived, I am easily able to accomplish by means of the construction shown in the drawings, as=for, instance by tilting the apparatus toward the right sufficiently to raise the outlet 15' above its position shown in Fig. IV, which will, owing to 9 the shape of the parts, result! in quickly raising the level of the pool in the crucible 4, thereby correspondingly increasing pressure from below upon the aggregation of refining materials and also contact ofthe 'molten iron therewith, after which, by tilting the apparatus in the opposite directio'n,-. the immersion of the refining materials in ment's both tending toimpart impulses to the aggregation of refining materials which assist in insuring renewed contacts and also descent thereofint-o the crucible and to the positions therein required for most effective operation.

That Iclaim as new and desire to secure v 'by'Letters Patent is the following, viz be dispensed with and the substantial segregation of the sa1d"produc ts from the bulk 50 -I 3 from the crucible proper effected by elimi- 11. The method of-partly refining molten pig iron which comprises movably supporting a normally continuous upwardlyextending pervious aggregation of independently movable units of refining material containingoxid of iron, directing into said refining; materials a stream of said iron, and inter- .mittently oscillating together, relatively to a common center, said iron and'said refin-- ing material, whereby desired reactions are promoted, descent of-said refining materials insured, and segregation of refined iron and resulting products from said refining material simultaneously effected.

2. The method of partly refining molten pig iron which comprises moyably supporting a normally continuous upwardly extending pervious aggregation of lndependently 139 movable units of refining material containing 'oxid of iron, directing into said refining materials a stream of said iron, accumulating said stream in a pool immersing the lower partio'l? said aggregation of refining materials, segregating said poolfrom the 'bulk of said refining material and in the meantime intermittently oscillating together, 'relat1vely to 'a' common center, said iron and said refining material, whereby desired 1'e-' act-ionsare promoted, descent of said refining material into sald pool insured, and segregations of refined iron and resulting proding the lower part of said aggregation of Y refining materials, passing through said pool a current of electricity, and intermittently oscillating together, relatively to a common center, said ironand said refining materials, whereby desired reactions are promoted, descent' of said refining materials into said pool insured, and segregations of refined iron and resulting products frbm said refining materials simultaneously efi'eeted.

4. The method of partly refining molten pig iron which comprises movably supporti'ng a normally continuous upwardly extending pervious ag egation of independently movable units 0 refining material containing (mid ,of iron, directing into said refining materials a stream of said iron, accumulating said stream in a pool, immersing the lower part of said aggregatio'n of refining materials segregating partly refined iron and resultin slag products from the bulk of said refining material and intermittently oscillating together, relatively to a common center, said iron, said refining materials and said'segregated iron and resulting products, whereby desired reactions and said segregation are promoted, descent of said refining materials'into-said pool insured and inter mittent deliveries of said partly refined iron and resulting products effected.

5. The method of partly refining molten pig iron which comprises movably supporting a normally continuous upwardly extending pervious aggregation of independently movable units of refining material containing oxid of iron, directing into said refining materials a stream of said iron, accumulating said stream in a pool, immersing the lower part of said aggregation of refining materials, segregating partly refined iron and resulting slag products from the bulk of said refinin material, passing a current of electricity cownwardly and horizontally through said pool and horizontally and up wardly through said segregated iron and resulting products, and intermittently oscillat ing together, relatively to a common center said iron, said refining materials and sai' segregated iron and resulting products, whereby desired reactions and said segregation are promoted, descent of said refining materials into said pool insured and intermittent deliveries of said partly refined iron and resulting products effected.

6. The method of partly refining molten pig iron which comprises movably supporting a normally continuous upwardly extendmg pervious aggregat on ofindependently movable units of refining mater1a contaming oxid of iron, directing into said refining materials a stream ofsaid iron, intermittently accumulating said stream in a pool lmmersing lower portions of said aggregation, and intermittently withdrawing said pool from said aggregation whereby descent of said refining materials toward positions where required is facilitated.

7. The method of partly refining molten pig'iron which comprises movabl supporting a normally continuous upWar 1y extending pervious ag regation of independently movable units oi? refining material contain ing oxid of iron, directing into said refining materials a stream of said iron,'accumulating said stream in a pool immersing lower per-- tions of said aggregations and then without materially addin to said pool imparting thereto changes of shape whereby it is cause alternately to more or less deeply immerse said refining materials.

JOHN B. Nan.

Witnesses: PHILIP C. PECK, GEOR E G. MEASURES.

opies of this patent may be obtained for five cents each, by addressing the Commissioner of Iatents,

. Washington, I). C. 

